Jet device



Oct. 25, 1 938. A. VAN DEN HONERT 2,134,460

JET DEVICE (INJECTOR OR EJECTOR) Filed Feb. 3, 1937 v 2 Sheets-Sheet 1 FIG: 7 76.?

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Oct. 25, 1938.

A. VAN DEN HONERT JET DEVICE (INJECTOR 0R EJECTbR) Filed Feb. 5, 1937 2 Sheets-Sheet 2 FIG 7 FIG-5:5

Patented Oct. 25, 1938 hisnsvr iszmmcmsdameme) l Heifer-1 Ti c l laglualNetherlands .This invention 'relates'to a jetdeviceiinjector or. ejector). in which the :driven or. pa e medium is forced into the path'of, the. driving or active medium, for thepurpose of transfer.-

ring the kinetic, energ er massyof .the .resultinggfiow With the, highest possible efficiency.

' Devices having this-same object are vlrnowrnin which the contents; grouped arounda cy cally brought; in ,front of a drivingyjet nozzle.

These devices allhave the disadvantage that. the flowthrough a large number oflnarrow chan-j nels causes a considerable loss vof.;energy by frice tion and the further disadvantage that it is necessary. to. use either a very, high nurnber of revolutions per. minu dimensions'in order the medium per unit i The object of the-present invention is to eliminate these disadvantages in such a .way; that, though the driven mediumis ,forced to enter the path of the drivingjeh thisds done without confining it in a plurality ofrotating;channels. Ac cording tothe invention the jetzof driving medium after leaving the nozzle, enters a -channel tangentially, or; approximately"tangentially, to a curved wall forming one of the sidesoipsaid channel, the suction opening for the passive rnei dium being located on the side of the nozzle op:

posite togthis curved Constructional examples of the. subject matter of the invention vention.

Fig. 2 is a cross section on the line IIII of Fig. 1.

Fig. 3 is a cross section on the line IIIIII of Fig. 4 is a cross sec tional form.

Fig. 1.

Figs. 5 and 6 show diagrammatically a constructional form in jet device is curved in two directions.

Figs. '7 and 8 are respectively, of a further modified constructional form.

'11 Ap'plication liebruary fi, 1937, "sena o. 123,923

, thehletlierla ndslibruary 8,1936

.walls. I y of the latter to the greatof-a number of channels, lindrical rotor, ,ar,e periodite 1 or a rotor of very large to work alargejvolume of time.

are illustrated in the acmedium results.

tion of a modified construcwhichv the passage of the a top plan and side View,

parabola.

corresponds or approximately corresponds to the thickness of the-driving .jet, while, the curved wall -12 is one of the edge or narrower side The other edge or narrow side wall It is par- 5 allelto thegendportion 'b of the curvedwall tie-by, and; thebroaddnlet-end 0-0! of thejet chamber is approximately parallel to the inlet end a of the curvedwall. into the jet chamber at the end, a of the curved wall Ctb, and .directsa jetof pressure medium tangentially of the curved wall and substantial- 1y transversely'of theyaxis of the jet chamber, as indicated by the arrowin Fig. 1. notedthat the driving jet is confined on only 15 threesidesgby the curved wall and the adjacent parallel side Walls. The open inlet c--d lies at the fourth side of'the driving jet.

.The jet of driving, medium emerging from the nozzle 8, and entering the channel at, a, tangentially ;to the; curved wall a b, tends to continueits movement in;a straight line. This tendency cause'sa depression along the curved wall (r b and in the driving 'jet itself. 7 The medium-situated, for example'at cg is set in motion 'by this pressure differenca toWards the, point oflowest pressure and thus is forced into the path of the driving medium. By; the collison' of driving and drawn in (passive) media, the direction of movement of both will-be altered,

resulting in only-one stream in which, the two 3 are completely mixed. The passive medium thus never reaches the point of lowest pressure and consequently the depression is kept up undiminished and an uninterrupted inflow of passive The resulting stream again causes a depression along'the next part of the curved wall, with the similar result of drawing in passive medium again.

The impulse of the resulting stream after the collision is the geometrical resultant of the two original impulses of driving and driven'media.

: The direction of the resulting stream is parallel to a tangent to the curved wall al-b'. vature of this wall, therefore, is to be calculated from the impulses of the two component streams of driving and driven media. For instance, if it be required that equal amounts of passive medium be'drawn in per unit of length of the suction opening c--d, the curve a-b should be a The nozzle s opens It is to be The cur- If the passive medium is a gas, the velocity of influx may, under certain circumstances, rise above the critical (sound) velocity. In this case the suction opening should show a contraction (6 in Fig. 4): it must consist of a converging and a diverging part, for the purpose of accelerating the gas movement, gradually to above the critical velocity, with as little loss of energy as possible. Figure 4 shows suction inlet of the kind in question.

It may be preferable, mainly for constructional reasons, to give the channel a curved shape instead of a fiat one, as shown in Figs. 1, 2 and 3. The channel may be bent, say into a cylindrical form, as shown diagrammatically in Figs.,5 and 6. The channel, in this case, is formed by the annular space 1, between the two cylindrical shells g and h. This annular space is shown in Fig. 5 as if it were a solid body. The curved wall, denoted by w-b in the flat channel of Fig. 1 here takes the shape of a helix with a varying pitch. (In Fig. 5 the same designation ab is used).

Various combinations are possible. Thus Figs. 7 and 8 show, diagrammatically, a combination of a number of jet devices working parallel with each other. Owing to the fact that these devices are arranged symmetrically around an axis, the driving jets being all directed towards this axis, the walls k: of Fig. 1, situated opposite the curved walls ab of the several channels, would coincide and may, therefore, be omitted entirely. The passive medium may, furthermore, be drawn in stages. If the first jet device be so dimensioned that only a portion of the total amount of passive medium is actually sucked in, the re sultant stream of this first jet device may act in a succeeding device as the driving jet. This may be repeated, thus obtaining a number of jet devices, arranged in series, worked by only one primary driving jeti What I claim is:-

1. In a jet device, a chamber having walls forming a channel open at both ends and of approximately rectangular cross-section, the side walls being substantially uniformly spaced and one edge wall being curved with its convex side towards the channel, and a nozzle at and substantially tangential to the inlet end of said curved edge wall for directing a jet of driving medium substantially transversely of the open end of the channel adjacent said nozzle, whereby the jet of driving medium is unconfined along one side and that open side serves as the suction inlet for the passive medium.

' in the side walls of said chamber at the suction inlet converge toward and then diverge from each other in the direction of flow, thereby to accelerate the motion of the passive medium gradually to a velocity above the critical gas velocity with a minimum loss of energy.

3. A jet apparatus as claimed in claim 1, wherein the side walls of said chamber are curved transversely, thereby imparting a curved shape to the channel.

4. A jet apparatus as claimed in claim 1, wherein the side walls are concentric helical surfaces.

5. A jet apparatus as claimed in claim 1, wherein the Wall means of said chamber define a plurality of channels arranged symmetrically about and merging into each other along a central axis, the curved wall of each channel being spaced from the axis and the several nozzles being directed towards the axis.

6. A jet apparatus as claimed in claim 1, wherein said nozzle produces a jet of driving medium having a thickness substantially equal to the Width of the channel. 7

7. In a jet device, a chamber having walls forming a channel having an inlet end and an outlet end, a nozzle at the inlet end of said channel fordirecting a jet of a driving medium substantially transversely of the open inlet end of the channel, one wall of the chamber being tangent to the nozzle and convexly curving progressively from the nozzle, whereby the reduction in pressure at the surface of the curved wall deflects the jet of driving medium to flow along the curved wall and thereby produce a moving stream of reduced pressure, the mass of the stream being continuously increased by the sucking up of passive medium through the unconfined side of the stream.

8. The invention as claimed in claim '7, wherein the cross-section of said channel is approximately rectangular, the walls of said chamber adjacent said curved wall being uniformly spaced from each other.

9. The invention as claimed in claim 7, wherein the cross-section of said channel is approximately rectangular, the walls of said chamber adjacent said curved Wall being uniformly spaced from each other and curved to define a helical channel.

AUGUST VAN DEN HONERT. 

